Slotted deflector flap



May 17, 1938. R. w. GRlswoLD--izn 2,117,607

SLOTTED DEFLECTOR FLAP Filed Alvlg. 4, 1956 2 Sheets-Sheet l IN V ENTOR.

A TTORNEY May 17 193,8- R. w. c aRlswoLD, 2D 2,117,607

SLOTTED DEFLECTOR FLAP Filed Alg. 4, 1936 2 Sheets-Sheet 2 INVEN TOR.

ATTORNEY Patented May 17, 1938 NUNITED STA-'rasv PATENT oi-FlciztoUnited- Aircraft Corporation, East Hartford, Conn., a corporation ofDelaware y Application mmm 4, 193s, seri.: Nn. 94,1s9

yzivlaims.

This invention relates to lift increasing devices l for airplanes,andfha's particular reference to a wing construction arranged to providefor an increased lift when the airplane is operating at wing liftincreasing devices of the type 'known as slotted aps. v

In the slotted ap type the iiap is so positionedv relative to the fixedwing that a wing slot is formed by the curved under surface of the fixedwing and the leading edge of the ap. A wing slot is a passage extendingthrough the wing having a larger entrance gap at the lower surface thanexit gap at the upper surface, such relation usually being termed theslot coniinement ratio or slot nozzle eiect, and having' such passage sodirected that the ow from the lower surface may enter'the slotirrespective of its angular relation to the direction ofthe free streamow but may only discharge from the exit gap'in the direction of andsubstantially parallel to the upper surface ow. It has beenA found inpractice that a wing slot having a confinement ratio between the valuesof five to one and ten to one has good aerodynamic proportions. Theseare not necessarily limiting values of the connement ratio but, atpresent, are believed to give the best eiliciency.

An object of this invention is to obtain an improved llftincreasing'device.. v

A further object is to extend the lift increasing I eiiect of theslotted ap over a large range of flap angles.

A still further object is to effectively maintain Va wing slot of goodaerodynamic proportion lr- 40 respective of angular position of thevilap.

In the accompanying drawings in which like reference numerals are usedto designate similar parts throughout, there is illustrated, somewhatschematlcallyf-a suitable embodiment of what is now considered to be thepreferred 'form of the idea of the invention and two somewhat modifiedforms thereof. The drawings, however, are for the purpose ofillustration only andare not to be taken as limiting the invention, thescope of which is to be measured entirely by the scope of the appendedclaims.

In the drawings, Fig. 1 ls a partly schematic sectional view of the rearportion of an airplane wing constructewaccdrding to the ideaof' thiscontrol of the aircraft;

(ci. 244-42) f invention showing the lift increasing lflap in itsneutral or .normal night position;

Fig. 2 is a view similar to Fig. 1 showing' the flap in its half-nap ornormal take-oir position;

y Fig. 3 is a view similar to Fig. 1 showing the' 5 flap in itsfull-ilap or maximum angular position for landing or gliding;

Fig. iis a partly schematic sectional view similar to Fig. 1 showing asomewhat modified form of lift increasing ap construction; ,f 10

Fig. 5 is a. partly schematic sectional view similar to Fig. 1 showing asomewhat modied fom Aof the idea of the invention in which the liftincreasing device is also utilized for securing-lateral i l5 Fig. 6 is aview similar to Fig. 'showlng the main lift increasing ap in adownwardly inclined F 'or lift increasing position;

Fig. 'l isa somewhat schematic illustration of the manually operablemeans for actuating the` zo improved lift increasing device to providelateral control of the aircraft. r

' Referring to the drawings in detail, the nui meral I0 generallyindicates a. xed wing portion. the broken away rear portion of which isillus- 25 trated. This fixed portion may be provided with a rear sparschematically indicated at I2 to which is hinged a movable full trailingedge flap 4I4 mounted to pivot Vabout the point I6. 'I'he ap isconstructed with aselected airfoil section. 'I'he 30 rear edge of thefixed portion- I2 of the wing has f l an extension which provides arearwardly and upwardly directed curved surface I8 at the rear edge ofthe xed portion which overlles the forward surface of the movable flap,and provides 35 between these surfaces a slot which decreases in-V widthfrom bottom to top, is generally inclined rearwardly, and is provided atits upper end with a restrictedoutlet 2li, asillustrated in Fig. 1,lsucha slot, of good aerodynamic characteristics 40 will have aconfinement ratio of from between' 5and10to1. ,1 A slot closure door 22is hingedly secured at the lower portion of the rear edge of the xedwing portion Ill, as indicated at 2, and has two 45 operative positions.In the rst operative posif tion illustrated in Figfl, the undersurfaceof the slot closure door forms a continuation of the undersurface oftheiixed portion of the wing and of the undersurface of the movable nap,and m effectively closes the bottom opening of the slot.- When the partsare in the relation illustrated in Fig. 1 with the trailing edge iiap inits uppermost position and the slot closure door in its lowermostposition, the wlw in effect an ordinary 55 solid wing of unbrokenselected airfoil contour,

and has substantially no drag loss over that of an ordinary solid wing.

In its alternative operative position, the door is inclined upwardlyagainst the rear of the fixed portion of the wing, as illustrated inFigs. 2 and 3, in which position it completely opens the bottom of theslot and its undersurface constitutes a por- `tion of`one side of theslot. When the slot closure door isrin the operative positionillustrated. in Figs. 2 and 3, the maximum amount of, air can flowthrough the slot provided between the rear edge of the fixed prtion ofthe wing and the forward edge of the/,trailing edge ilap.

The construction so far described provides the advantage of increasedlift when theftrailing edge flap. is tilted without the disadvantage ofmaterially increased drag when the trailing edge ilap is in its neutralor normal flying position.

A deflector plate 26, which may be of airioil section, is positionedimmediately above the upper portion oftlie 4forward edge of the trailingedge flap Il, and is secured to the trailing edge ap by suitablesupports, as indicated at 28. the deflector platevbeing thereby ilxed toandmovable with the trailing edge ap. This plate is so arranged Ythat aslot oi' selected aerodynamic characteristics is provided between theundersurface of the plate and the upper surface of the forward edge ofthe wing trailing edge flap, the.

slot between the plate and ap'being in general a continuation of theslot between the rear edge of the ilxed portion of the wing and theforward edge of the trailing edge ilap. The upper surface of the,deilector plate 28 'is constructedto move within the curved upper rearsurface of the .xed wing portion. The eiect of the deilector' plate, asis clearly apparent from the illustration in Figs. 1, 2, and3, is tocurve andextend the slot betweenv the fixed portion of the wing and themovable trailing edge ap as the ap is inclined downwardly to therebyeiectively' maintaina wing slot of good aerodynamic proportionsirrespective of the angular position of the flap.

.The effect of this construction is to control the -airjiow over theupper surface of the flap by reason of the change of direction andacceleration of the flow of the air passing through the slot and thus ahigh velocity airflow is directed over the upper surface of the wingtrailing edge flap at all flap positions vwithin a wide range of hapmovement, the range illustrated in the drawings being from approximatelyzero to 45.

With this construction, the maximum lift eiIect can be obtained from thetrailing edge flap at this and greater angles without stalling the apand having the air break away from the upper iiap surface and therebycause the ilap to lose its lift.

Preferably, the deilector plate 26 is so located with respect to theforward edge of the wing trailing edge flap and the rear ledge ot thexed portion of the wing, that when the slot closure door 2z is in itsuppermost position, a slot exit is provided along both the upper andlower surfaces of the deflector plate. As stated above, this deectorplate .may be either a simple'curved plate or fj conventionalairfoiicontour, and as the -air acquires high velocity in owing throughthe slot this defiector plate becomes, when the slot is open, a highlyenergized airfoil which maf terially assists in improving the overalllift characteristics of the wing by helpingv to maintain an unbrokenflow overthe upper surface of main ilap, as indicated at 36.

hydraulic uid under pressure to the opposite ends of the `cylinder 32 sothat the trailing edge flap I4 may he manually adjusted from one toanother of its various operative positions.

The slot closure door 22 is likewise operated by suitable means, such asthe hydraulic expansible chamber device 38. This device includes acylinder 40 pivotally connected at one end to the fixed portion of theWing, as indicated at 42, and provided with a reciprocable piston towhich is connected a rod 44, the free end of whichfis pivotallyconnected to the slot closure ilap, as indicated at 46. The supply ofhydraulic fluid to the cylinder 40 is also manually controlled sothatthe slot closure door 22 may be moved from one to the other of itsoperative positions at the will of the operator of the vehicle uponwhich the lift increasing construction is provided. Separate manualcontrol of the wing trailing edge ilap and the slot closure door hasdistinct advantages in that it gives independent control of the twodevices at the will of the operator.

While the improved construction has been il- `lustrated and so fardescribed as applied entirely y have particular application to aileronswhich may be held in a downwardly inclined position or drooped tor thepurpose of increasing the lift ,of the wing, and it is within the scopeof the invention to cover a construction in'which the wing is providedover a portion of its span with a ilap, or aps, constructed according tothe idea illustrated in the drawings and described above, and over otherportions of its span with ailerons which maybe drooped when the flap istilted downwardly to assist the flap in increasing the liftcharacteristics of the wing.

From this description it will'be observed that the construction asdescribed above provides the advantage, long sought after in the art, ofmaterially increasing the lift characteristics oi the wing, particularlyat relatively low .air speeds, without the consequent disadvantagesinherent in the prior art.

In the modified form of the invention shownin Fig. 4, the slot closuremember, as indicated 4at 50, is hingedly attached at'the upper rearward-portion of the xed win portion, as indicated at respects, 4such asl therange of lift increasing eifect, to the form illustrated in Figs. 1, 2,and 3, its greater simplicity of construction and economy of parts mayrecommend its use in certain inclosure member 22 is also'hinged at thelower4 portion of the rearward edge of the fixed wing portion in themanner-described above, and both the slot closure memberand the trailingedge ap are movable by suitable means, such as is illustrated in Figs.1, 2, and 3 and described in connection therewith, such means beingomitted from Figs. 5 and 6 for the sak'e of clearness in theillustration.

In the modiiiedform of the invention as illustrated in Figs. 5, 6, and'7, the guide vane 26', instead of being rigidly attached to the forwardlportion of the trailing edge ap, as provided in the form of thevinvention illustrated in Figs. 1, 2, and 3, is hingedly connected tothe upper portion of the rear edge of the `fixed wing portion to tiltabout an axis indicated at 64. The movable ,guide vane 26 is providedwith an extension 56 to the outer end of which is pivotallly connectedone end of a link member 58 the opposite end of whichy is pivotallyconnected to a disk or crank member 60 rotatably mounted in the rearwardportion of the fixed wingportion. The disk member 60, the link 58, andthe extension 56 are so arranged that upon` rotation of the disk 60 themovable guide vane 26' may be tilted aboutthe axis 54 to any positionwithin a range oi' movement indicated by the full line and dotted linepositions-of the guide'vane in Fig. 5. If necessary, a depression 51 maybe provided in the flap to allow clearance for the fextension 56 andattached end of the link 58.

The disk 6B isA rotated by'means of a cable 62 v. operatively connectedwith a lever member 64 which is, in turn, rigidly connected with a gearsector 66. 'I'he `teeth of the gear sector 66 mesh with the teeth of agear member 68 operatively connected by suitable means, such as thechain 10,`with-the hand wheel 12 customarily employed f the same mannerthat the ailerons ordinarily' employed are disposed. Each movable guidevane is actuated by a separate cable, the two cables being indicated at62 and 62' in Fig. 7. The ends of the cable-62' are connected to a levermember 64', similar to the levermember 64, whichis in Aturn rigidlyconnected with a gear sector.66, similar to the gear sector 66,.andmeshing with the teeth of the gear 68 upon the opposite side of the gear68 from the gear sector 66. The gear 6B is a mutilated gearvand "isprovided over a portion of its circumference with an arcuate cam portion14 which cooperates with complementary cam portions 16 and 16 on theAgear sectors 66 and 66 respectively in such manner that only one of thegear sectors will be operated at a time. As illustrated inimg. '1, ifthe hand wheel 12 be rotated'in a clockwise direction, gear 68 willrotate counterclockwise andthe gear sector 66 will be moved to changethe position of the guide vane section -to which the cable 62 isattached, while the cam portion '14will slide upon the cam portion 16'of the gear sector 66' so that the gear sector 66 will notbe moved. Ifthe wheel 12 be rotated in a counterclockwise direction, the gear sector46,6 will be maintained stationary, and-thegear sector 66 ,will be movedto adjust the position of the movable guide vane to which the cable 62is attached. By this means, the movable guide vanes will be moved overarange extending only from the neutral position I illustrated in fullylines in Fig. 5 to their upper position illustrated in dotted linesinthat figure, and the effect of adjusting the guide vanes will be tourge downwardly the wing half upon which 'the guide vane being actuatedis located. The guide vane mounted -upon` the opposite half 'of the wingmaintains its neutral position and that half of the wing tends tomaintain itself level with respect to the airplane.

As the movable guide vane sections are `mounted adjacent to the upperopening of the slot proe vided between the trailing edge flap-and thefixed portion of the wing, the effect of the guide vanes when tiltedupwardly above-their neutral position will be that of a lift spoilersince the air i, flowing along the upper surface of the xed por--v tionof the wing and the air flowing through the half upon which it ismounted, thus giving to the lateral control of the airplane an effectknown will greatly increase the resistance of vthe wing v as positiveyaw. The combined elfect of the wing half vmay be manually *controlledto eiect.

lateral and directional trim of the aircraft.

'I'he eeet of the movable guide vane sections is dependent to aconsiderable extent upon the position of the slot closure. member 22,their effect being much more pronounced when the slot closure member isopen than when it is vclosed and also increasing with the downwardinclination of the main trailing edge ap I4.

This relation gives a particularly desirable condition for controllingthe aircraft. For instanceI when the aircraft is climbing at arelatively slow airspeed with the slot closure member 22 in its4uppermost position and the main trailing edge flap i4 tilteddownwardly, 4the effect upon the lateral Scontrol of the aircraft of themovable guide vane sections 26 4will be at` its maximum. As it is highlydesirable to have the controlling effect of the aircraftcontrol surfacesat the maximum when the airspeed is low, it willv be seen that thisarrangement offers that particular feature of advantagezf When the slotclosure member 22 is in itslowermost position and the` sectionwill be atthe minimum, both as to lift spoiling and drag.. This is also adesirable condition since at -high air speeds very slight eftectl of thecontrol surfaces is necessary to obtain the desired amount ofmaneuverability, and an excessive amount causes unnecessarily heavyloads upon the manual control apparatus and also renders the aircraftoversensitive in its response to the controls.

`flap mechanism in the manner described in con'- nection with Figs. 1,2, and 3, but may also be used as ailerons to provide for lateralcontrol of the aircraft in ight, thus doing away with the necessity forthe provision of the usual form of ailerons and rendering it entirelypractical to extend the lift increasing flap construction for the entirespan of the wing in combination with which the construction is employed.

A While there has been illustrated and described a particular mechanicalarrangement exemplifying the idea 'of the invention, it is to beunderstood that the invention is not to be limited to the particulararrangement so illustrated and described, but that such changes in thesize, shape, and arrangement of parts may be resorted to as come withinthe scope of the appended claims.

Having now described the invention so that others skilled in the art mayclearly understand the same, what it is desired yto secure by LettersPatent is as follows.

What is claimed is:

1. A wing lift increasing device comprising, a

manually actuatable tiltable iiap constituting a hingedly mounted partof the rear portion of the Wing spaced from the fixed wing portion toprovide a re-energizing wing slot between the fixed wing portion and theiiap, and a curved defiector plate projecting at its forward edge intosaid slot at all operative positions of said flap to direct there-energizing slot discharge along the upper surface of said ap.

2. A wing lift increasing device comprising, a tiltable iap constitutinga hingedly mounted part of the rear portion of the wing spaced from thefixed wing portion to provide a wing slot between the fixed wing portionand the flap, a curved deiiector plate mounted on said ap and projectingat its forward edge into. said slot in all positions of angularinclination of the ilap, said deflector plate being so shaped and sopositioned on said ap as to provide between said plate and saidVV flap aspace having selected aerodynamic characteristics for increasing thevelocity of the air at the exit end of said space between the rear edgeof said plate and the adjacent portions of the upper surface of saidflap.

3. A wing lift increasing device comprising a tiltable flap constitutinga hingedly mounted part of the rear portion of the wing spaced from thethe fixed wing portion and the flap, a door pivotally secured to thefixed wing portion in position 4. In a wing lift increasing device, atrailing edge flap spaced to provide a wing slot between said flap andthe xed portion ofthe wing, and means for extending and curving saidslot at the discharge end thereof.

5. In a wing lift increasing device, in combination with a trailing edgeflap spaced to provide a wing slot between the flap -and the wing, meansfor extending and curving said slot to discharge ir flowing through saidslot along the upper surface of said flap in all positions ofinclination of said fiap, and means for opening and closing said slot.

6. In a wing lift increasing device, in combinawing slot between theflap and the wing, means for extending. and curving said slot todischarge air flowing through said slot along the upper surface of saidflap in all positions of inclination of said flap, said means beingeffective to increase the velocity of the air flowing through said slot.

7. A wing lift increasing device comprising, a tiltable flapconstituting a part of the rear portion of said wing, manuallycontrollable means Aoperative to open and close an air flow aperturebetween the xed portion of said wing and said flap, an independentlyvmovable member associated with each half of said wing and extending intosaid aperture in all operative positions of said flap for normallydirecting the air flowing through said aperture over the upper surfaceof said flap to retain the lii't increasing liunction thereof over theentire operative range of ilap inclination, and manually operable meansoperatively associated with each of said movable members to move saidmembers to positions in which they reduce the lift of the respectivewing halves on which theyare mounted.

8. In a wing lift increasing device for aircraft comprising, a tiltableflap constituting a part of the rear portion of said wing and locatedwithA respect to the fixed portionof the wing to providea wing slotbetween the fixed wing portion and the ap, a movable guide vaneassociated with each lateral.half of said wing and constituting aportion of the discharge end of said slot in all operative positions ofsaid flap for normally directing air owing through said aperture overthe upper surface of said flap to maintain .the lift increasing eiect ofsaid flap at all operative positions thereof, manually actuatable meansfor operating said guide vanesas ailerons to provide lateral control forthe aircraft employing said wing lift increasing device by spoiling thelift of the wing and ap portions with which the respective guide vanesare associated, and means manually operable independently of said flapand said guide vanes for opening and closing said slot.

9. A variable lift wing comprising a relatively fixed portion having arearward projection and a relatively movable portion underlying saidprojection and spaced from said xed portion to provide an upwardly andrearwardly sloped and tapered slot between said portions, and adefiector plate on said movable portion ,spaced therefrom to provide atapered slot fixed with respect to said movable portion andunderlyingsaid projection in all operative positions of said movable portion tomaintain the f continuity of the slot between said portions. (L

10. A variable lift wing comprising a relatively fixed portion having arearward projection, and a relatively movable portion underlying saidprojection and spaced from said xed portion to provide a rearwardly andupwardly sloped and tapered slot between said portions,and a deiiectorplate secured to said movable portion in position to underlie saidprojection in all operative positions of said movable portion relativeto said fixed portion to provide a restricted slot exit gap xedrelatively to said movable portion and to maintain the continuity ofsaid slot up to said exit gap. A

11. In a variable lift wing, a relatively fixed portion having arearward projection and a relatively movable portion at the rear of saidxed portion underlying said projection and spaced from said fixedportion to provide an upwardly and rearwardly sloped and tapered slotbetween said portions, and a defiector plate on said mov- 'able portionunderlying said projection and spaced therefrom to provide aslot'portion xed with respect' to said movable portion and continuouswith the slot 'between said portions, and a second slot portion betweensaid .deilector plate and said projection in all operative positions ofsaid movable portion.l

12. In a winglift increasing'device a trailing edge llap spaced' toprovide a wing slot between said flap and the fixed portion ofthe wing,and means extending into the upper end of said slot in all operativepositions of said flap to shape said slot to prevent the stall of saidflap. Y

13. In combination, an airfoil, a flap spaced from said airfoil, and adefiector plate movable with said flap and located in the space betweensaid iiap and airfoil in all operative positions of said flap.

14. In combination, an airfoil, a lift-increasing ap movable through apredetermined range relative to said airfoil and spaced therefrom toform a wing slot therebetween leading from the lower to the upper sideof said airfoil andilap combination, and means extending into thedischarge end of said slot in all operative'positions of said flap todivide said slot at its discharge end into a plurality of exits.

15. In combination, an airfoil, a lift increasing ap movable through apredetermined range relative to said airfoil and spaced therefrom toform a wing slot therebetween leading from the lower to the upper sideof said airfoil and flap combination, and means for preventing the stallof said iiap comprising a deflector, a part of which at all timesunderlies the rear portion of said airfoiI for providing a plurality ofexits at the discharge end of the slot directed in the normal directionof air flow along the upper surface of said airfoil and of said flap. V

16. In combination an airfoil, a lift increasing flap movable through apredetermined range relative to said airfoil for. increasing the lift ofsaid airfoil and spaced therefrom to form a wing slot therebetween. adeiiector constructed and arranged to extend into said slot at all flappositions to provide a plurality of rearwardly discharging slot exits,one of which exits has a substantially constant ldirection relative tosaid wing and another of which exits changes its direction in accordancewith the movement of said flap.-

17. A variable lift wing 'comprising pivotally Y connectedrelativelymovable portions of airfoil lsurface of the rearward portion at aconstant angle'with respect thereto, said forward portion having arearward projection of such an extent as to overhang the leading edgefofsaid deector plate in all operative positions of said wing portions withrespect to each other.

18. In a variable lift wing having a basic airable flap portion forincreasing the lift coefficient Y foil contour a relatively fixedportion and a movofthe wing, Isaid fixed portion having a recessassociated with said curved rear edge. saidv deiiector having itsleading edge spaced forwardly and downwardly from said rear edge anangle distance about the axis of movement of said flap at least as greatas an angle including the range of operative movement of said flap. A i

20. In combination a wing, an airfoil movable relative to said wing tovary the aerodynamic characteristics of said wing and airfoilcombination and constructed and arranged to form vwith said wing a liftincreasing wing slot having an exit end, and a plate associated withsaid airfoil constructed and arranged to extend the exit end of saidslot and retain the integrity thereof in all operative positions of saidairfoil to thereby maintainV the lift increasing properties of said slotwith respect to said airfoil.

21. In a wing combination including a relatively fixed portion and arelatively movable portion associated in a `spanwise direction to' pro--vide between the adjacent surfaces of said portions an aerodynamic slothaving a relatlvelywide air entrance opening at the lower surface ofsaid wing combination and curved converging side v Walls for causingacceleration of-the air iiow through said slot and to provide arelatively vnarrow, air exit opening at the upper surface of said wingcombination directed .substantially parallel to the upper surface ofsaid wing combination for discharging air at increased velocity iri thedirection of airow over said upper surfaceand a deector plate associatedwith said relatively movable pcrtion and positionedat least partiallywithin said slot at all operative positions of said relatively movableportion formaintaining the integrity of said slot and for extending saidslot and maintaining said air exit opening directed substantiallyparallel to the upper surface of said relatively movable portion in alloperative positions ofsaid portions.

22. A variable lift wing comprising airelatively fixed portion and arelatively movable portion spaced to provide a rearwardly and'upwardlysloped and tapered wing slot therebetween, and members telescopicallyassociated in all operative positions of saidmovable portion withrespect to Asaid fixed portion,` mountedy on saidA respective wportionsto maintain the integrity of said slot throughout the operative range ofmovement of said movable portion with respect to said fixed portion. a

- 23. In combination, an airfoil, a lift increasing flap movable througha predetermined range relative to said airfoil and spaced therefrom toform a wing slot therebetweenleading from the lower to the upper sidevof'said airfoil and ap combi-l nation, and means extending at leastpartiallyy within said slot in all operative positions of said 10 vide awing slot therebetween, manually controllable means operative to mintaina substantially unbroken airfoil contour for said wing or to open saidwing slot, and a curved guide vane carried by said ap and extending intosaid wing slot in all positions of inclination of said flap to receiveair flowing through said slot along both 5 the upper and lower surfacesthereof to maintain a flow of air along .the upper surface of the flapin all positions o f inclination of the ap, and to constitute of itselfa highly energized airfoil.

ROGER W. GRISWOLD, n.

